Photocontrollers are employed in certain lighting systems to activate a light when ambient light is low and to deactivate the light when ambient light is sufficient. For example, a photocontroller for use with an outside light may turn on a light at night and turn off the light during the day. Controlling a light in such fashion can reduce the amount of energy consumed by the light and, in turn, reduce energy costs for the lighting provider.
However, if the photocontroller or a component thereof fails, power may be provided to the light continuously even during sufficient lighting conditions. For example, a relay used to switch the light on and off may fail in a closed position, or, a sensor used to detect ambient light may fail in a state that provides an indication of night or insufficient lighting continuously. If left undetected, these faults can result in large amounts of wasted energy.
Alternatively, a component of the photocontroller may fail in a position that results in the light never being activated. The relay used to switch the light on and off may fail in an open position or a sensor used to detect ambient light may fail in a state that provides an indication of daylight or sufficient lighting. This may result in a safety hazard.